1. Field of the Invention
The present invention relates to building construction devices that provide drainage and reduce cracks within masonry coatings such as stucco. More specifically, the present invention relates to an improved movement control screed that is structured to operate as a control joint for absorbing movement in a masonry coating and also as a weep screed to provide drainage of water from within and behind the masonry coating.
2. Description of Related Art
Expansion control joints and foundation weep screeds are commonly known in the masonry construction arts. FIG. 1 depicts an exemplary expansion control joint 20 in accordance with the known prior art. Expansion control joints are used to break up large areas intended for receiving masonry coatings such as plaster, stucco, and the like, into smaller masonry coated areas for purposes of relieving stress and resisting cracking. The depicted expansion control joint 20 includes metal lath first and second flanges 25, 30, and metallic first and second ribs 30, 32 defined between the first and second flanges 25, 30. The metal lath flanges 25, 30 are typically attached to an exterior wall surface (not shown). First and second masonry coatings 42, 44 are applied to the exterior wall surface using the first and second ribs 30, 32 of the expansion control joint 20 as a guide for the applied thickness of the coatings. The first and second ribs 30, 32 of the expansion control joint 20 are symmetrical and deflectable for absorbing movement between the first and second masonry coatings 42, 44 during curing or other thermally induced expansion and contraction.
FIG. 2 depicts a foundation weep screed 70 structured in accordance with the known prior art. The foundation weep screed 70 is attached to an exterior wall 54 that is comprised of plywood sheathing 56 and attached to a wall frame 55 just above a concrete building foundation 60. Foundation weep screeds 70 are commonly produced from sheet metal and positioned at the base of the exterior wall 54 for supporting a masonry coating (not shown) and providing a barrier that prevents water from coming into contact with the exterior wall 54.
The depicted foundation weep screed 70 is secured to the base of the plywood sheathing 56. The foundation weep screed 70 includes a flange 72, and a rib 75. The rib 75 defines an extending portion 74 for supporting an applied masonry coating and a returning portion 76. The extending portion of the rib 75 begins generally adjacent the foundation transition 61 and tapers downwardly as shown. A drip edge DE is defined between the extending and returning portions 74, 76 of the rib 75. Water resistant building paper 62 is typically positioned over the exterior wall 54 and the flange 72 for directing moisture from behind the masonry coating and over the foundation weep screed 70. Moisture can get behind the masonry coating at improperly sealed joints (e.g., at doors or windows) or because of cracks that may form in the masonry coating. If left unchecked, such moisture may cause rotting of wooden structures within the wall. Installation of foundation weep screeds 70 as described above create a moisture path extending down the building paper 62, along the flange 72, and over the extending portion 74 of the rib 75 to the drip edge DE as shown.
In the wake of severe storms such as hurricanes, many jurisdictions have modified their building codes to require significant reinforcement of first level exterior walls. Typically, this reinforcement is provided by constructing first level exterior walls from reinforced concrete or other similar materials. Such walls provide enhanced wind and impact resistance. However, building codes continue to allow upper floors and roof structures to be made from wood trusses that rest on top of the concrete reinforced exterior walls. In this regard, wall transitions are now defined between dissimilar wall materials (e.g., wood and concrete) used for upper and lower floors. Accordingly, it would be desirable to prevent moisture from entering such wall transitions. It would also be desirable to support masonry coatings applied above and below the wall transitions and to absorb movement of the masonry coatings such as might occur during curing or thermal expansion and contraction of the coatings.